82nd United States Congress
Senate

State (class)
Vacator
Reason for change
Successor
Date of successor's formal installation
Kentucky (2)
Virgil Chapman (D)
Died March 8, 1951. Successor appointed March 19, 1951 to continue the term.
Thomas R. Underwood (D)
March 19, 1951
Michigan (1)
Arthur H. Vandenberg (R)
Died April 18, 1951. Successor appointed April 23, 1951 to continue the term.
Blair Moody (D)
April 23, 1951
Nebraska (2)
Kenneth S. Wherry (R)
Died November 29, 1951. Successor appointed December 10, 1951 to continue the term.
Fred A. Seaton (R)
December 10, 1951
Connecticut (3)
Brien McMahon (D)
Died July 28, 1952. Successor appointed August 29, 1952 to continue the term.
William A. Purtell (R)
August 29, 1952
Connecticut (3)
William A. Purtell (R)
Retired upon special election. Successor elected November 4, 1952.
Prescott Bush (R)
November 5, 1952
Kentucky (2)
Thomas R. Underwood (D)
Lost election to finish the term. Successor elected November 4, 1952.
John S. Cooper (R)
November 5, 1952
Michigan (1)
Blair Moody (D)
Lost election to finish the term. Successor elected November 4, 1952.
Charles E. Potter (R)
November 5, 1952
Nebraska (2)
Fred A. Seaton (R)
Lost election to finish the term. Successor elected November 4, 1952.
Dwight Griswold (R)
November 5, 1952
Maine (1)
Owen Brewster (R)
Resigned December 31, 1952. Seat was not filled during this Congress.
Vacant
Vacant
California (3)
Richard Nixon (R)
Resigned January 1, 1953, after being elected U.S. Vice President. Successor appointed to continue the term.
Thomas Kuchel (R)
January 2, 1953

Question: Who succeeded Virgil Chapman in March 1951, and who succeeded them in 1952? 
Answer: Virgil Chapman (D) was until March 8, 1951 and Thomas R. Underwood (D) is from March 19, 1951 until November 4, 1952 where John Sherman Cooper (R) is from November 5, 1952.